Equine Endoparasites Flashcards
Name three cestodes of horses
Anoplocephala perfoliata
A. Magna
Paranplocephala mamillana
Name the intermediate host of cestodes.
Oribatid mite
Describe the lifecycle of A. perfoliata.
- Infected mite ingested by the horse
- After 2 months adult worms are present at the ileo-caecal junction
- Proglottids gravid with eggs are passed in horses faeces
- Proglottids disintegrate and release eggs which are ingested by oribatid mite
- Eggs develop within the mite to cysticercoid
- Mites are found in soil, shavings and hay (and are v small)
Describe the morphology of A. perfoliata eggs.
D-dhaped
~50-80 um
Onchosphere is supported by pyriform apparatus
Describe the morphology of adult A. perfoliata.
Where in the equine SI are they found?
- Short broad segments
- Lappets behind each four suckers
- Adults are found at the ileo-caecal junction
What are the clinical signs associated with A. perfoliata infection?
What associated condtions?
C/S
- Ulceration of intestine
- Ill thrift
- Enteritis
Associated conditions:
- Spasmodic colic
- Itussuscpetion
- Ileal impaction/ rupture
What ages are most affected by A. perfoliata?
Which time of year is most associated with A. perfoliata infection?
- Less than three have highest level of infection but all ages are affected.
- Autumn/ winter are peak levels but all times of year are possible.
How is A. perfoliata infection diagnosed in the horse?
- FEC (only around 60% sensitivity)
- ELISA detects Ag (95% specificity)
- Parasite excretory/secretory Ag
- IgG
Describe a treatment plan for A. perfoliata infection.
Double dose pyrantel
Praziquantel
Giant roundworm
aka
Ascarids
Which stage of the ascarid lifecycle is infective?
L2 found within the egg
True or False.
Ascarid eggs are highly resistent to death outside the host.
True
Where in the horse can Ascarids be found?
(x2)
What are the potential effects of the infection?
- Small intestine
- Compete with horse for nutrients
- May cause mechanical blockage
- Migrating - hepato-tracheal migration
- Stimulates ++ inflamm response
Describe the morphology of a Parascaris equorum egg.
Round and thick walled with undiff morula in the centre.
Outline the lifecycle of Parascaris equorum.
- Eggs are passed onto pasture
- L2 develops within the egg (takes about 4 weeks but is temp dependent)
- Egg is eaten by the horse
- L2 migrates to the liver and then lung, developing to L3
- L3 is coughed up and reswallowed, develops from L4-L5 in the SI